Three dimensional particles identification and shape parameters research on coarse aggregates of asphalt mixture using X-ray CT images

In this paper a series of digital image processing methods were adopted for getting separated coarse aggregates from asphalt mixture specimen using high-resolution X-ray Computed Tomography (CT) images.The existing three dimensional (3D) particles matching methods based on two dimensional (2D) continuous cross-sections were analyzed and a new ’overlap area method’ was presented.After the 3D particles were extracted one by one successfully,the basic parameters of each aggregate:perimeter,area,surface area,and volume were calculated by chain code method.Finally,the 3D mass center coordinates and the sphericity index were introduced.     

基于CT图像的粗集料颗粒接触特性细观尺度研究

采用工业CT获取沥青混合料断面扫描图像,利用数字图像处理方法将粗集料从图像中分离,并解决了颗粒粘连问题,使粗集料颗粒成为单独个体.确立了粗集料颗粒之间接触的判定准则,并设计5像素×5像素大小的窗格沿颗粒边缘进行接触搜索.对640张断面图像遍历处理后获得的数据进行定性分析,尝试建立了接触度指标C.采用4种概率密度分布函数...     

基于CT断层扫描图像的混凝土粗集料三维虚拟筛分

分析了基于数字图像进行混凝土级配分析的主流方法的局限性,并说明了采用工业CT技术手段的独特优势。按照沥青混合料粗集料分级粒径范围制作了5个试件,利用工业CT扫描获取粗集料体积参数。对3类集料体积数字计算方法的准确性进行了比较。通过球面调和变换表征粗颗粒的三维表面轮廓,并在此基础上获取L、W维度位置,并截取出通过筛孔控制平面。经过一系列数字图像处理手段,最终判定集料所能通过的方孔筛的筛孔大小。验证结果表明,基于CT断层扫描图片可以较准确地实现混凝土粗集料的三维虚拟筛分。